It has been heretofore proposed to modify living cells so as to obtain cells differing in function or biochemical output. Thus, normal cells have been changed to cancerous cells by exposure to mutagenic influences. For the production of useful biochemicals or the enhancement thereof, normal cells have been hybridized with malignant cells or altered in genetic makeup by the insertion of viral material.
Metal ions have been applied to cells, as for instance, silver, associated with various anions or anion complexes, or free of anions. However, except for Netien et al., U.S. Pat. No. 3,337,405, which teaches a thereapeutic effect on tissue for complexed silver ion, and Mironenko et al., U.S.S.R. Author's Certificate No. 322,202, which teaches an unspecified therapeutic effect of silver ions from silver salts on certain viscera, application of silver ions to cells or tissue, for treatment or pharmacological purposes, has been for the purpose of disinfection. Aside from natural processes, such as cell metabolism in which certain metal ions play a part, metal ions are generally considered to fall into the categories of inert, toxic, and mutagenic, with respect to cells. Silver as such, aside from cosmetic effects, is now generally regarded as inert, or at least harmless insofar as human tissue is concerned. The use of silver ions against bacterial infections is described in "Silver Anode Treatment of Chronic Osteomyelitis" by D. A. Webster et al., Clinical Orthopedics and Related Research, Number 161, November-December, 1981, pp. 105-114 and in "Treatment of Orthopedic Infections With Electrically Generated Silver Ions" by R. O. Becker et al., Journal of Bone and Joint Surgery, vol. 60-A, No. 7, October 1978, pp.871-881.
In testing the use of silver ions against bacterial infections in chronic osteomyelitis, a silver nylon electrode, in contact with the wound, was made electrically positive with respect to the surrounding tissue of the patient. Passage of a low level direct current through the electrode for a period of three hours per day, with normal wound care for the reset of the time, resulted in a satisfactory drop in bacterial counts. To distinguish between the effect of the wound treatment, since it might be the effective agent rather than silver, I began treating for twenty-four hours a day. Results with a few patients seemed to be the same, so I went to twenty hours a day. This resulted in an enhancement of the effect against bacteria, the appearance of an exudate, and markedly increased rates in wound healing. Subsequent analysis has shown that an heretofore unappreciated effect is produced by the application of current for an extended period of time by which the silver promoted both a cell modification akin to dedifferentiation and mitotic activity.